Gingrich, who is trying to revive his presidential campaign, defended his comments in a Republican debate Monday with a forceful argument that drew a standing ovation from the audience. On Tuesday, his campaign used the moment to try to raise money, producing a Web video that highlighted the candidate’s response.

“More people have been put on food stamps by Barack Obama than any president in American history,” Gingrich says in the video, set to soaring music. “I’m going to continue to find ways to help poor people learn how to get a job, learn how to get a better job and learn someday to own the job.”

To his supporters, his statement captures his appeal as a politician — his rhetorical skills and willingness to tackle politically tricky issues.

But his critics see something more sinister in his language as he seeks to regain lost ground in South Carolina, where strains of racial antipathy linger and where candidates have sometimes resorted to racially charged attacks to gain favor.

“It’s no secret that Gingrich is fighting for his political life,” said Wade Henderson, president of the Leadership Conference on Civil and Human Rights. “In a craven effort to regain his relevance, he’s turned to subtle but age-old tactics of racial invective to feed his base.”

By using the term “food stamp president,” Henderson said, Gingrich is evoking a stereotype similar to that of the “welfare queen,” a term used in the latter part of the 20th century to conjure images of a black single mother on welfare, without specifically mentioning gender or race.

In the debate, Gingrich said bluntly that he sees no reason his comments should be taken as insulting to poor people or blacks. And his supporters say he is simply offering creative policy prescriptions to address the nation’s ills.

“To hear him speak is a breath of fresh air because . . . he says it straight up,” said Dianne Belsom, a tea party activist in South Carolina who has endorsed Gingrich’s candidacy and who attended the debate.

She said the audience rose in support of Gingrich on Monday because people were unhappy that the moderator, Fox News journalist Juan Williams, raised the specter of race. “This whole campaign is not about race,” Belsom said. “It’s about saving this country.”

For months, Gingrich has been racheting up his attacks on Obama’s handling of the economy, arguing that the president is fostering an underclass that is dependent on the government. He has asserted that the country needs bold ideas — for example, putting poor children to work in schools.

He has cited the New York City schools, where he alleges that a janitor can earn more than some teachers. By employing students to do “light janitorial work,” he says, the students could learn a work ethic and earn a little money.

Gingrich earned the ire of the Service Employees International Union, which represents the New York schools’ custodial staff. It said Gingrich was overstating janitors’ salaries. Typical cleaners are paid about $37,000 annually, the city’s school system told the New York Times on Tuesday; a custodial engineer, who is certified to fix certain equipment, may make three times that amount.

On Tuesday, White House spokesman Jay Carney said it was “crazy” to accuse the president of putting people on food stamps. While there has been an increase in the number of people receiving government assistance, he blamed the recession, whose roots, he said, were sowed by policies favored by Gingrich.

This month in New Hampshire, Gingrich singled out blacks for receiving food stamp assistance, saying that he was prepared to speak before the NAACP to “talk about why the African American community should demand paychecks and not be satisfied with food stamps.”

While it is true that the number of people enrolled in the Supplemental Nutrition Assistance Program, or SNAP, hit an all-time high in 2011 at almost 46 million, more than a third of recipients are white, according to the U.S. Department of Agriculture. Twenty-two percent are black, 10 percent are Hispanic, and 19 percent are from unknown ethnicities.

Gingrich is no stranger to these issues. As House speaker, he played a significant role in overhauling the nation’s welfare system and was an outspoken advocate for school reform.

And he has gone out of his way to show solidarity with African Americans and ideological opposites on issues of race, embarking on a tour with the Rev. Al Sharpton in 2009 to draw attention to the achievement gap between students of different races and socioeconomic status.

Gingrich’s recent rhetorical turn has upset Sharpton, who on his MSNBC show last month said: “You should know better, Newt. In fact you do know better. . . . He’s repeating the central principle of this mean-spirited Republican Party: protect the rich, attack the poor.”

Staff writers David Nakamura, Nia-Malika Henderson and Krissah Thompson contributed to this report.